1. Field of the Invention
The present invention relates to an image forming apparatus, a data transfer system and an information management method for the apparatus and the system, and in particular, to an image forming apparatus used in a network environment, a data transfer system constructed in such a network environment, and an information management method for such an apparatus and a system.
2. Description of the Related Art
In a network environment constructed in an office and the like, an image forming apparatus such as a copying machine, a printing machine, or a MFP (Multi Function Peripheral) as a digital complex machine having functions of copying and printing machines is typically used. Depending on a configuration of the network, a single image forming apparatus can be used by a plurality of client apparatuses. In a case in which a plurality of image forming apparatuses and a number of client apparatuses are included in a network, it is also conceivable that each image forming apparatus exchanges data with all of the client apparatuses.
As one application of such an image forming apparatus in a network environment, for example, an image forming apparatus and a client apparatus are used together to realize a function in cooperation such that the client apparatus outputs an instruction to the image forming apparatus and the image forming apparatus outputs specified image data.
In order that an image forming apparatus and a client apparatus are used together to realize a function in cooperation, it is required that the image forming apparatus holds information relating to client apparatuses that are connected to the network. If the network includes a plurality of image forming apparatuses and all the client apparatuses use each image forming apparatus, it is required that each image forming apparatus holds information relating to all of the client apparatuses. In Japanese Laid-Open Patent Publication No. 2006-334870 that has been previously filed and is already published, the present applicant discloses a technique relating to a function that a plurality of image forming apparatuses included in a network share information relating to client apparatuses without using a server.
When the network includes a number of client apparatuses, assuming that each image forming apparatus holds information relating to all of the client apparatuses, each image forming apparatus must have a memory having a large capacity. This disadvantageously hinders cost reduction of an image forming apparatus.
Each of the image forming apparatuses connected to the network stores information relating to the client apparatuses of a number corresponding to an amount of its memory. Accordingly, when an amount of information relating to the client apparatuses that is stored reaches the maximum amount of memory of an image forming apparatus having a capacity that is the largest among that of the image forming apparatuses connected to the network, a problem occurs that, even if the network includes a plurality of image forming apparatuses and a total amount of memory for the network as a whole is large, a client apparatus that is connected to the network over the number corresponding to the amount of memory of the image forming apparatus having the largest capacity cannot exchange data with any of the image forming apparatuses.
Moreover, when a single image forming apparatus stores information relating to a number of client apparatuses and the image forming apparatus is operated to exchange data with one of the client apparatuses, as many options as the number of the client apparatuses that are stored in the information are presented. This, as a result, makes an operating procedure complex and can results in a faulty operation, disadvantageously causing an operation different from an intended one.